That is almost certainly an assembly number of some kind on the cylinder, not the serial #. ETA: Value varies by lots of factors, including location, but I am confident you did well.
Savage559: as a new shooter, welcome. You have what appears to be a nice first purchase. Some of the more collector oriented folks will have a purist approach to the grips, but there are also Neanderthals like me who worry more about fitting my hand, comfort, and other functional issues. That revolver is a K frame, with a square butt. It is probably more capable of accurate performance than most of us reading the string, myself included.
The ammo: what is its source? Is it factory, or someone's reloads? I ask because while a skilled attentive reloader can do a great job, a slob reloader can make up some stuff that is not good for you or the gun. There are MANY people here who can educate you past that point, and there are a lot of discussions of that and other issues.
Do a lot of reading in the forum before you get ready for your first range trip. You can learn a lot without having any of the risk of uneducated errors. You may find that lighter loaded target ammo in .38 special will be less of a chore for a new shooter. .38 Special ammo is the predecessor to the .357; the main difference is that the .357 case is longer to prevent loading this higher performance ammo into .38s, so of which are not capable of standing the higher pressure.
Make sure you have a real understanding of safe firearms handling. KNOW and live by the four safety rules, first espoused by Jeff Cooper as far as I know: 1) All guns are always loaded; 2) never point a gun at anything you are not willing to destroy (kill); 3) keep your finger off the trigger until you are on target and prepared to shoot, 4) know your target and backstop (be sure of what your bullet will hit and where it will go after). These are paraphrases.
If you give us a general location, the odds are good that a member here will know of a decent place to get initial instruction, possibly including themselves. Shooting is a great hobby, and can have many enjoyable and practical positives. However, we are also responsible for everything we do with a firearm, and it is a big responsibility since we can do a lot of harm. If one is careless and does harm from ignorance, the harm is no less.
Welcome.